1. Technical Field
The present invention relates to an image forming method, a liquid developing device, and an image forming apparatus.
2. Related Art
A method of using a liquid developer having toner particles dispersed in an insulating liquid to form an image on a recording medium has been proposed as an image forming method.
In the method using the liquid developer, the cohesion of toner particles is effectively prevented, as compared to a method of using dried toner, and thus it is possible to use minute toner particles and use a binding resin having a low softening point (low softening temperature). As a result, an image forming apparatus using the liquid developer can form a fine line image, a gray-scale image, and a color image with high reproducibility.
In general, a material having high chemical stability, such as petroleum hydrocarbon or silicon oil, is used as an insulating liquid used for the liquid developer.
However, the method using the liquid developer has a problem in that the insulating liquid adhered to the surfaces of toner particles during fixation sinks in the recording medium, which causes the strength of fixation to be lowered. The sinking of the insulating liquid makes it difficult to perform an additional writing on the recording medium with, for example, a ball-point pen.
In order to solve these problems, a technique for using naturally-derived oil and fat, such as vegetable oil, as an insulating liquid and using an oxidation polymerization reaction of the oil and fat for fixation is disclosed in JP-A-2000-162829.
However, in the technique disclosed in JP-A-2000-162829, an oxidation polymerization accelerator for accelerating an oxidation polymerization reaction, such as metal salt of fatty acid, is used to improve fixation characteristics. However, the oxidation polymerization accelerator deteriorates the color of a formed image and thus it is difficult to apply the oxidation polymerization accelerator to develop colors.